In an uplink time difference of arrival (U-TDOA) location system (and other location systems), location performance is normally expressed as one or more circular error probabilities. The United States Federal Communications Commission (FCC) as part of the Enhanced 9-1-1 Phase II mandate requires that network-based systems, such as U-TDOA systems, be deployed to yield a precision that generates a one-hundred meter (100 m or 328.1 feet) accuracy for 67% of emergency services callers and a three-hundred meter (300 m or 984.25 feet) accuracy for 95% of emergency services callers. Overlay network-based wireless location systems have been widely deployed in support of location-based services including emergency services location. The installation and tuning of such systems can require manual entry of myriad configuration parameters derived from operator supplied data, manual site surveys and measurements, topographical and geographical analysis and simulations. The system information, geographic information, cabling details and radio settings that can be collected during the planning and installation phases of deployment are shown below in Tables 1 and 2.
Table 1 identifies top-level information on the wireless communications system and all individual Base Stations, Node-B or Access point sites. The information requested in each field should be provided by the wireless network provider or operator for every Base Station, Node-B or Access Point site in the to-be deployed market. Once collected, this information forms the basis of the Serving Mobile Location Center (SMLC) database as well as part of the accuracy prediction modeling. In the tables below, references to TruePosition refer to the assignee of the present application, TruePosition, Inc.
TABLE 1System and Base Station Site DataDatabase ColumnCommentData EnteredSystem IDSystem ID for the switch that is hosting this BaseNumerical Value(MCC + MNC)Station/Node B or AP site. (SS7 Identifier)System IdentifierThe System Identifier field is eight octets in length,Numerical Value (ifand contains the identifier of the system (TCP/IPavailable)Identifier) note: An SS7 identifier or a TCP/IP addressis required.Base Station IDThe alphanumeric BCFID that identifies the BaseAlphanumeric TextStation cell site.RF BandIndicates what band this Base Station site is using. 0 = 850 MHz,Numerical Values1 = 1900 MHz, 2 = 900 MHz, 3 = 1800 MHz,4 = 2100 MHz, 5 = 700 MHz, 6 = 450 MHzBSC IDAlphanumeric Base Station Controller ID assigned byAlphanumeric Textthe Wireless Operator to identify the Base StationController (GSM only)RNC-IDRadio Network Controller Identifier (UMTS only)Alphanumeric TextMSC IDThe Mobile Switching Center ID that consists of a 1 toAlphanumeric Text3 digit E.164 Country Code (CC), a 3 digit NDC, and avariable number (also known to the Wireless Operatoras Mobile Switching Center ISDN).Cell SiteWGS-84 Latitude of the Base Station site antennas, inNumerical ValuesLatitudedecimal degrees format with a resolution of 10−6degrees. (dd.dddddd)Cell SiteWGS-84 Longitude of the Base Station site antennas,Numerical ValuesLongitudein decimal degrees format with a resolution of 10−6degrees (ddd.dddddd)GPS AGLHeight above ground level, in meters, of the GlobalNumerical ValuePositioning System antenna. If no Global PositioningSystem (GPS) antenna is currently installed, insertzero (0).LMU Site AntennaEnter the type of site: 1 = tower, 2 = monopole,Numerical ValueDescription3 = Remote antennae, 4 = Distributed Antenna site
Table 2 identifies an entry for each cell or sector in each base station site identified in the market. If multiple sectors are used at a site, data should be provided, as a separate record, for each sector. If multiple air interface technologies are used at a site, data should be provided, as a separate record, for each air interface and each sector using that technology. Table 2 is presented here with the assumption of 3-sectors per cell site or less. Additional sectors will result in additional columns.
TABLE 2Base Station Site Sector DataDatabase ColumnCommentALPHABETAGAMMASector IDSector identifier. 1 - Alpha, 2 -Numerical ValueNumerical ValueNumerical ValueBeta, 3 - Gamma. For omni-directional sites, this shouldalways be 1.Sector ActiveIndicates if the sector isNumerical ValueNumerical ValueNumerical Valuecurrently active within thesystem. 0 = No; 1 = YesAntenna TypeIdentifier of the antenna type.Numerical ValueNumerical ValueNumerical ValueSet to zero (0) if this is anomni antenna, set to one (1) ifa sectorized antenna.Antenna GainAntenna gain in dB. DecimalNumerical ValueNumerical ValueNumerical Valueformat with a resolution of 10−2.in dBiin dBiin dBi(dBi format)Antenna AzimuthAzimuth in degreesNumerical ValueNumerical ValueNumerical Valuein degreesin degreesin degreesAntenna TiltDepression angle in degrees.Numerical ValueNumerical ValueNumerical ValueNegative value denotesin degreesin degreesin degreesantenna uptilt. (Combinedelectrical and mechanical)Antenna LatitudeWGS-84 Latitude in decimalNumerical ValueNumerical ValueNumerical Valueformat with a resolution of 10−6degrees (dd.dddddd)Antenna LongitudeWGS-84 Longitude in decimalNumerical ValueNumerical ValueNumerical Valueformat with a resolution of 10−6degrees (ddd.dddddd)Antenna aboveHeight of ground above MeanNumerical ValueNumerical ValueNumerical ValueMean Sea LevelSea Level of structureantennas are mounted to(e.g., tower, building, etc.), inmetersAntenna AGLHeight of antenna relative toNumerical ValueNumerical ValueNumerical ValueantennaAmsl, in metersHorizontalHorizontal beamwidth of theNumerical ValueNumerical ValueNumerical ValueBeamwidthreceive antenna with ain degreesin degreesin degreesresolution of 0.1 degreesVerticalVertical beamwidth of theNumerical ValueNumerical ValueNumerical ValueBeamwidthreceive antenna with ain degreesin degreesin degreesresolution of 0.1 degreesIndoor CoverageIndicate whether the sectorNumerical ValueNumerical ValueNumerical Valueprovides only indoor coverage0 = No; 1 = YesMulticoupler GainMulticoupler gain in dB.Numerical ValueNumerical ValueNumerical ValueDecimal format with a(in Db)(in Db)(in Db)resolution of 10−2Cable LengthRadio frequency cable lengthNumerical ValueNumerical ValueNumerical Valuein meters -Jumper 0 Dx1/Dx2Radio frequency cable lengthNumerical ValueNumerical ValueNumerical Valuein meters - Feeder Dx1/Dx2Radio frequency cable lengthNumerical ValueNumerical ValueNumerical Valuein meters - Jumper 1 Dx1/Dx2Radio frequency cable lengthNumerical ValueNumerical ValueNumerical Valuein meters - Jumper 0 Tx3Radio frequency cable lengthNumerical ValueNumerical ValueNumerical Valuein meters - Feeder Tx3Radio frequency cable lengthNumerical ValueNumerical ValueNumerical Valuein meters - Jumper 1 Tx3MCCThe mobile country codeNumerical ValueNumerical ValueNumerical Value(MCC) identifies the country inwhich the GSM PLMN islocated. The value of the MCCis a 3-digit number assignedaccording to E.214 numberingplan. (GSM only)MNCThe mobile network code is aNumerical ValueNumerical ValueNumerical Valuecode identifying the GSMPLMN in that country (GSMonly)LACThe Location Area Code is aNumerical ValueNumerical ValueNumerical Valuefixed length code (of 2 octets)identifying a location areawithin a GSM PLMN. (GSMonly)RACThe Routing Area IdentifierNumerical ValueNumerical ValueNumerical ValueCode is a fixed length of 1octet and identifies a routingarea within a location area(GPRS and UMTS)SACService Area Code - A 2 octetNumerical ValueNumerical ValueNumerical Valueelement used to uniquelyidentify an area consisting ofone or more cells belonging tothe same Location Area(UMTS only)CGIThe Cell Global Identity is theNumerical ValueNumerical ValueNumerical Valueconcatenation of the LAI(Location Area Identity) andthe CI (Cell Identity) anduniquely identifies a given cellCell IdentifierThe Cell Identifier is a 2 octetNumerical ValueNumerical ValueNumerical Valuelong hexadecimal identifierthat identifies a cell within alocation area. (GSM only)CIThe cell identity is a 16 bitNumerical ValueNumerical ValueNumerical Valueidentifier in GSM and UMTS.When combined with the LAI(Location Area Identity) or RAI(Routing Area Identity) theresult is termed the CGI (CellGlobal Identity).
Over the years, the terminology used to describe wireless location technology has evolved. The uplink radio receiver system, originally called the Signal Collection System (SCS), is now sometimes referenced using the 3GPP-defined terms Location Measurement Unit (LMU) and Position Determining Entity (PDE), standardized by the Telecommunications Industry Association (TIA) and later 3GPP2. Similarly, terms used to describe wireless communications networks vary with the AMPS/TDMA/CDMA term “Cell Sector” equivalent to the GSM term “Cell Global Identifier” (CGI), the UMTS term Cell Identity (CI) and the IEEE terms “Access Point” (AP) or Base Station (BS). Certain wireless communications network terms are used interchangeably depending on whether they refer to the usage (e.g. “Beacon”), the standardized term (e.g. “BCCH”) or the identifier associated with the antenna (e.g. CGI).
Moreover, given the rapid change in the types of wireless communications systems (cellular, SMR, unlicensed band and mobile-network-virtual-operators (MVNOs) the term “operator” and “carrier” are herein described as the generic term, “wireless network provider” or WNP. Even TruePosition's TDOA and AoA core high accuracy location product naming has changed in the last decade from the “Wireless Location System” (WLS) to “Location Network” and now to “TruePosition Location Platform” (TLP).
The inventive techniques and concepts described herein apply to time and frequency division multiplexed (TDMA/FDMA) radio communications systems including the widely used IS-136 (TDMA), GSM, and OFDM wireless systems, as well as code-division radio communications systems such as CDMA (IS-95, IS-2000) and Universal Mobile Telecommunications System (UTMS), the latter of which is also known as W-CDMA. The Global System for Mobile Communications (GSM) model discussed below is an exemplary but not exclusive environment in which the present invention may be used.